Ion mobility spectrometers (IMS) can identify material from a sample of interest by ionizing the material (e.g., molecules, atoms, etc.) and measuring the time it takes the resulting ions to reach a detector. The ion's time of flight is associated with its ion mobility that relates to the mass and geometry of the molecule that was ionized. Ion mobility spectrometry operates at around ambient atmospheric pressure and separates ions with respect to mobility in the presence of a drift gas. The detector's output can be visually represented, for example, as a plasmagram of peak height versus drift time.
Mass spectrometers (MS) operate in a vacuum and separate ions with respect to charge/mass ratio. In some embodiments using a mass spectrometer, a sample, which may be solid, liquid, or gas, is ionized. The ions are separated in a mass analyzer according to mass-to-charge ratio and are detected by a device capable of detecting charged particles. The signal from the detector is then processed into the spectra of the relative abundance of ions as a function of the mass-to-charge ratio. The atoms or molecules are identified by correlating known masses by the identified masses or through a characteristic fragmentation pattern.
Each detection system may include a sample source, an ion source, an analyzer, and a detector. Some examples of ion sources, which may include a device that creates charged particles (the ions), may include electrospray ionization, inductively-coupled plasma, spark ionization, a radioactive source (e.g., 63Ni), etc.